Severe lipodystrophy linked to pembrolizumab

Treatment with the immune checkpoint inhibitor (ICI) pembrolizumab can induce lipodystrophy with severe metabolic complications, according to a case study.

A 47-year-old woman received pembrolizumab to treat metastatic melanoma and developed immune-related generalized acquired lipodystrophy. The condition has persisted 12 months after she stopped taking pembrolizumab.

The patient was diagnosed with BRAF-mutated, stage IV melanoma with bone and lymph node metastases. She received pembrolizumab at 2 mg/kg every 3 weeks as first-line treatment. She achieved a complete response and was still in remission at last follow-up.

The patient was obese at baseline, with a body mass index of 40 kg/m2, but she did not have diabetes, hepatic steatosis, or dyslipidemia.

Within 2 months of starting pembrolizumab, the patient observed “some major changes to her physical appearance,” according to Dr. Delyon and colleagues. At 10 months, the patient had severe lipodystrophy.

The patient experienced a change in fat distribution – namely, severe peripheral lipoatrophy and an accumulation of trunk fat. Imaging revealed a decrease in subcutaneous adipose tissue, which contrasted with an increase in visceral fat observed from baseline.

The patient also developed “moderate hirsutism, facial and limb atrophy, and prominent forearm and leg muscles and veins,” according to the authors. She had impaired glucose tolerance with insulin resistance, reduced concentrations of leptin and adiponectin, hypertriglyceridemia, a low level of HDL cholesterol, and hepatic steatosis.

Analyses of subcutaneous fat revealed adipose tissue atrophy with edema, lipophages, and CD3+/CD4+ T-cell infiltration of the fat and vessel walls. This suggested that the lipodystrophy had an autoimmune origin, according to the authors.

The patient had no family history of autoimmune disease or lipodystrophy. She tested negative for mutations in 23 genes associated with generalized lipodystrophy.

The patient also tested negative for HIV, antinuclear antibodies, native anti-DNA, and anti-insulin receptor antibodies. There were no signs of panniculitis, and the authors noted that “there were no arguments in favor of hyperthyroidism, Cushing syndrome, or acromegaly.”

In an attempt to reverse the lipodystrophy, the researchers stopped pembrolizumab treatment. The patient was treated for diabetes and hypertriglyceridemia as well. She could not receive corticosteroids because of the risk of severe metabolic complications, and she didn’t receive metreleptin because it wasn’t available. The patient still had lipodystrophy 12 months after stopping pembrolizumab.

Dr. Delyon and colleagues wrote that this case suggests pembrolizumab, and perhaps other anti–programmed death 1 therapies, may cause lipodystrophy with severe metabolic complications. “The long-term side effects of such metabolic adverse events, although rare, are unknown and will probably become a topic of utmost importance, considering the increasing rate of remission following ICIs and their use in the adjuvant setting.”